The vision for Birmingham's city centre in the 1960s showed a coherence that often seems absent from much of today's piecemeal development.

The best of 1960s architecture was set well back from the pavement edge, landscaping was often designed as an integral part of the plan and vistas were considered a significant aspect of the desired cityscape.

Take Smallbrook Queensway. Standing in the island at the bottom of Holloway Head, you get one of the best views of 1960s Birmingham, much of it designed by James Roberts.

From here it is clear that this was conceived as representing a city wall, marked by The Sentinels on Holloway Head at one end and the 'medieval keep' of the Rotunda at the other.

The wide pavements create a wonderful spacious feel and repetition of key features in the buildings on either side of the road make links between them while tree-planting softens their confident blockiness.

Where will we find such vistas among the developments of early 21st century Birmingham? Certainly not in the results of in-filling around Centenary Square.

From outside the entrance to the Library of Birmingham, you see new development in every direction.

Centre City is a dominant landmark on Smallbrook Queensway

To your left are the buildings replacing the Central Library in Paradise - what a misnomer.

Opposite the library stands the grade II-listed Alpha Tower (1970), designed by Richard Seifert of Centre Point fame.

This 'iconic feature of Birmingham's skyline' is rapidly disappearing within the welter of new high-rise buildings which surrounds it.

The old Municipal Bank, also grade II-listed, is dwarfed, its grandeur lost.

Both listed buildings have been robbed of the space in which to stand proud and be appreciated.

To the right rises the blue-glass, 24-storey, Hyatt Regency Hotel.

Opened in 1990, the exterior remains intact, but we have lost the pleasure of enjoying the curvy design of Alpha Tower reflected in its glass façade.

Next door to the library is Graham Winteringham's Repertory Theatre (1969-71), a radical departure from traditional theatre design.

Its brutalist-style architecture reflects its purpose, a light and entertaining combination of glass and concrete in an upside-down arcade pattern, giving plenty of light to the foyer areas with their splendid cantilevered staircases.

Beyond the REP is Symphony Hall and the International Convention Centre (1991), with its glass and stone exterior.

Sympathetically designed, it sat comfortably alongside its neighbours in terms of its appearance, height and size, which is not something that can be said of the Library of Birmingham, shoe-horned into the north side of the square, dominating and quarrelling with its neighbours, the Repertory Theatre and Baskerville House.

Centenary Square was a major civic achievement advertising Birmingham's rightful place as the Second City by showcasing innovative architecture in a grand setting.

Today it is a jumble of buildings that seem to be vying with each other. There is little respect for the overall effect. What has happened to our civic pride?

Let's now move to a different and little known area around the back of the library. Enjoy a few moments of quiet in the Peace Garden before you head down Brindley Drive.

The ground falls away and you enter the tranquil and expansive landscape of Civic Centre Estate, extending down to the canal.

Four residential tower blocks are sympathetically placed to maximise housing density without compromising the spaciousness of the area.

The site was given a Civic Trust Award in 1969.

The Flapper pub next to the canal network has been saved from demolition - for now (Image: Nick Wilkinson)

Standing by the canal, look left and right - what a contrast. Across the canal to your left, mature trees soften red-brick low rise residential building, allowing for a delightful, open vista.

To your right, high-rise buildings crowd to the very banks of the canal, turning it into a gloomy, sunless, windy canyon rather than the welcoming public amenity which could be Birmingham's most attractive feature, a green parkway threading through the city.

Walking to your left you come to The Flapper public house, built in the late 1960s. The pub was designed to provide the kind of leisure amenity that redeveloping the canals could create.

Formerly called The Longboat, it is recorded to have been the first of the new purpose-built waterside pubs in England. Turned down for statutory listing, The Flapper is now under threat.

A recent planning application for its demolition and the creation of a 12- and five-storey block in its place would have irretrievably altered the spacious feel of this area and begun the process of extending the 'canyon' effect.

The planning application has been withdrawn but it is likely that further applications will be lodged.

Unsympathetic piecemeal infilling is going to ruin Birmingham's cityscape and impact on the health and wellbeing of us all.

Birmingham missed a trick in failing to celebrate the Central Library and allowing its demolition.

Let's not miss the unique opportunity presented by our canals and the few remaining later 20th century buildings, which speak so forcefully of the growth and optimism of this key period in Birmingham's history.

Green spaces, interesting vistas and an attractive skyline call for respectful treatment of the environment when new developments are being considered.

Now is the time to think twice about sacrificing everything to square footage and consider how we might make best use of the city's existing assets.

Mary Keating represents Brutiful Birmingham which campaigns for the preservation of the city's best late 20th century buildings